Production method for a delaminatable laminated bottle

ABSTRACT

A particularly small eyedropper or the like is provided, which has a construction such that, when a body thereof is squeezed, an introduction hole thereof can be easily closed to compress air in a space between an inner layer and an outer layer thereof even in the absence of a check valve in the introduction hole, and defectiveness of the introduction hole can be easily checked. To this end, a test hole ( 19 ) communicating with an introduction hole ( 17 ) via a space between an outer layer bottle ( 1 ) and an inner layer bag ( 16 ) is provided in an outer layer mouth portion ( 4 ). The test hole ( 19 ) is closed by the inner layer bag ( 16 ) and an inside plug ( 21 ) fitted in the mouth portion ( 4 ). Further, the introduction hole ( 17 ) is provided in a middle portion of a body which is pressed by a finger when the bottle is squeezed. The introduction hole ( 17 ) is closed by the finger.

TECHNICAL FIELD

The present invention relates to a delaminatable laminated bottle whichincludes an outer layer and an inner layer provided on an inner surfaceof the outer layer and delaminatable from the outer layer, and aproduction method for the delaminatable laminated bottle.

BACKGROUND ART

The inventors of the present invention have proposed delaminatablelaminated bottles of the aforesaid type as disclosed in the followingpatent publications 1 to 6.

Patent Publication 1: JP2001-146260-A Patent Publication 2:JP2001-114328-A Patent Publication 3: JP2001-105477-A Patent Publication4: JP2001-105478-A Patent Publication 5: JP2001-146260-A PatentPublication 6: JP2002-263166-A

These prior art delaminatable laminated bottles do not requirepost-processing such as melt-processing or piercing for forming an airintroduction hole in an outer later after injection molding of apreform, because the formation of the air introduction hole is achievedwith the use of a pin provided in a mold. This is advantageous in thatthe molding process is simplified and the production is achieved byutilizing an existing production plant which is modified simply byproviding the pin in the mold, thereby reducing plant costs. Without theneed for the post-processing, there is no possibility of contaminationof products with foreign matters due to the post-processing, so thatthese delaminatable laminated bottles are advantageously utilizedparticularly as cosmetic containers and medical containers such aseyedroppers. In the prior art delaminatable laminated bottles, a checkvalve for preventing back flow of air in the air introduction hole isdefined by an inner layer mouth portion, thereby achievingsimplification of the construction and reduction of the costs.

In order to ensure the functions of the delaminatable laminated bottleand prevent distribution of defective products, it is supposedlyimportant to check for assured formation of the air introduction hole.However, there is no established check method. Particularly for themolding of a small bottle having a volume of about 10 ml, high levels ofaccuracies are required in various aspects. Therefore, it is primarilyimportant to establish a defective check method.

Where the prior art is applied to a small eyedropper having a volume ofabout 10 ml and the inner layer of the eyedropper has a thicknesssufficient for proper functioning, the ratio of the inner layerthickness to a mouth diameter is increased. Hence, there is apossibility that the inner layer does not properly function as the checkvalve. Further, where the introduction hole is formed in a bottle body,the introduction hole is liable to be closed when the bottle body isdrawn in a blow molding process. Therefore, it is desirable to establishthe check method.

DISCLOSURE OF THE INVENTION

It is therefore an object of the present invention to provide adelaminatable laminated bottle which has a construction such that,particularly when it is embodied as a small eyedropper, an introductionhole thereof can be easily closed to compress air between an inner layerand an outer layer thereof by squeezing a bottle body even in theabsence of a check valve in the introduction hole and defectiveness ofthe introduction hole can be easily checked, and to provide a productionmethod for the bottle.

To attain the aforementioned object, the present invention has thefollowing technical features.

A delaminatable laminated bottle according to the present inventioncomprises: an outer layer bottle having a squeeze-deformable bottomedtubular body, a shoulder portion and a mouth portion connected to anupper edge of the body via the shoulder portion; an inner layer bagprovided on an inner surface of the outer layer bottle and delaminatablefrom the outer layer bottle; the outer layer bottle having anintroduction hole for introducing outside air into a space between theouter layer bottle and the inner layer bag; the mouth portion having atest hole communicating with the introduction hole via the space betweenthe outer layer bottle and the inner layer bag; and a member fitted inthe mouth portion and having an outlet passage for dispensing contentsof the inner layer bag, the member pressing the inner layer bag againstthe test hole so that the test hole is closed by the inner layer bag andthe member.

According to the present invention, whether or not the introduction holeis assuredly formed is determined by checking for air flow from theintroduction hole when air is injected into the space between the outerlayer bottle and the inner layer bag from the test hole. Since the testhole is closed by the member (e.g., an inside plug or the like) and theinner layer bag, there is no possibility of the leakage of the air whichmay otherwise occur when the test hole is open during use.

In the inventive delaminatable laminated bottle, the body of the outerlayer bottle has a flat tubular peripheral wall which includes a pair offront and rear wall portions spaced a predetermined distance in opposedrelation and left and right wall portions respectively connecting leftand right edges of the front wall portion to left and right edges of therear wall portion, and has an anteroposterior thickness which is smallerthan a lateral width thereof. The left and right wall portions may eachhave an arcuate shape with an anteroposteriorly middle portion thereofbulged laterally outward. The body may further have an upper connectionportion which connects upper edges of the front and rear wall portionsto the shoulder portion, and a lower connection portion which connectslower edges of the front and rear wall portions to a bottom portionthereof. The introduction hole may be provided in a center portion of atleast one of the front wall portion and the rear wall portion. Theintroduction hole may be adapted to be closed by a finger when the bodyis squeezed to be deformed by pressing the front and rear wall portionsby the finger. With this arrangement, when the body of the outer layerbottle is squeezed to be deformed by holding the front and rear wallportions of the bottle on opposite sides of a minor axis thereof, forexample, by a thumb and a forefinger, the introduction hole isinevitably closed by the finger to pressurize the air in the spacebetween the inner layer and the outer layer. Therefore, the inner layerbag is shrunk by the pressurized air to dispense the content liquid.

More preferably, the front and rear wall portions may be rigid wallportions which each have a relatively great thickness, and the left andright wall portions may be flexible connection wall portions which eachhave a relatively small thickness. Further, the upper connection portionand the lower connection portion may be a flexible connection portionswhich each have a relatively small thickness. Thus, the right and leftedges of the front rigid wall portion are respectively connected to theright and left edges of the rear rigid wall portion via the flexibleconnection wall portions, and upper and lower edges of the rigid wallportions are connected to the shoulder portion and the bottom portionvia the flexible connection portions. When the front and rear rigid wallportions are pressed toward each other by two fingers, the entire bodyis squeezed to be deformed. Even if the bottle has a smaller volume, thebottle can be squeezed to be deformed so that the volume thereof isreduced to the half or smaller. Further, even if the bottle is thussqueezed to be considerably deformed, the bottle is less liable to bebroken because the left and right flexible connection wall portions andthe upper and lower flexible connection portions are elasticallydeformed. Therefore, a greater amount of content liquid can be dispensedat a time by squeezing the bottle. Further, the content liquid can bedispensed to the last drop from the delaminatable laminated bottlehaving the inner layer bag provided in the bottle.

The delaminatable laminated bottle having the aforesaid construction canbe produced by a conventionally known blow molding method. Thedelaminatable laminated bottle is configured so that the rigid wallportions each have a relatively great thickness and the right and leftconnection wall portions and the upper and lower connection portionseach have a relatively small thickness. By varying a blow ratio for therespective portions or varying a wall thickness of a bottle preform forthe respective portions, the rigid wall portions are imparted withrigidity so as not to be warped by a pressing force applied by thefingers, and the connection wall portions and the connection portionsare imparted with flexibility so as to be elastically deformed to followparallel displacement of the front and rear rigid wall portions. Outersurfaces of the rigid wall portions are preferably planar, but may beentirely slightly curved outward or inward.

To produce the bottle having the aforesaid construction by the blowmolding, the configuration of a shape imparting surface of a mold forthe blow molding is preferably modified. In the case of a conventionalso-called oval bottle blow-molding mold, for example, a shape impartingsurface of the mold is configured so that shape imparting surfaceportions of the mold on opposite sides of a minor axis of a body of themold are planar or convexly or concavely curved as having a greatercurvature radius than the wall portions on the opposite sides of theminor axis of the bottle body. The wall portions on the opposite sidesof the minor axis of the bottle body are formed at a lower blow ratio,and defined as the rigid wall portions each having a greater thickness,and wall portions on opposite sides of a major axis of the bottle bodyare formed at a higher blow ratio, and defined as the flexibleconnection wall portions each having a smaller thickness. Further, theshape imparting surface of the blow-molding mold is configured so thatprojections bulged anteroposteriorly outward are provided on upper andlower sides of the rigid wall portions. Portions of the bottle body onthe upper and lower sides of the rigid wall portions are formed at apartly greater blow ratio, and defined as the flexible connectionportions each having a smaller thickness.

Where the bottle is a blow-molded plastic bottle, it is preferred thatthe flexible upper connection portion and the flexible lower connectionportion are located anteroposteriorly outward of the rigid wallportions, and the average thickness of these connection portions issmaller than the average thickness of the rigid wall portions. Further,it is preferred that the lateral width of the body is greater than theanteroposterior thickness of the body, and the average thickness of theleft and right flexible connection wall portions is smaller than theaverage thickness of the rigid wall portions. Thus, the bottle can beeasily produced at lower costs simply by modifying the configuration ofthe shape imparting surface of the blow-molding mold as described abovewithout the need for alteration of the construction of the blow moldingapparatus and the blow process.

The bottle may be configured so that the body thereof has a laterallyelongated oval cross section and the rigid wall portions each have avertically elongated rectangular shape as seen from the front side. Theouter surfaces of the rigid wall portions each have a vertical length of20 mm or greater, preferably 25 mm or greater. In general, when thebottle body is held and pressed by the fingertips of the two fingers(the thumb and the forefinger), outer surface portions of the bottlebody to which a pressure is applied by the fingertips in contact withthe outer surface portions each have a vertical length of 1 cm orsmaller. In the case of the conventional squeezable bottle, only theportions of the bottle each having a length of about 1 cm in contactwith the fingertips are warped to be deformed when the bottle issqueezed by the two fingertips. Therefore, only a very small amount ofcontent liquid is dispensed. In the case of the inventive bottle, on theother hand, the rigid wall portions each having a vertical length of 20mm or greater are displaced inward of the bottle due to their rigidityto significantly reduce the volume of the bottle when the verticallymiddle portions of the front and rear rigid wall portions are pressed bythe two fingertips. Further, where the outer surfaces of the rigid wallportions each have a lateral width which is greater than one half thelateral width of the entire body (a distance between vertexes of theouter surfaces of the left and right arcuate connection wall portions)and greater than 10 mm, the rigid wall portions can be easily squeezedand, hence, the squeezability of the entire bottle body can be furtherimproved. Where the distance between the outer surfaces of the front andrear rigid wall portions is smaller than the lateral widths of the outersurfaces of the rigid wall portions, the left and right connection wallportions can be smoothly elastically deformed by increasing thecurvature radii of the left and right connection wall portions.

More preferably, the left and right connection wall portions and theupper and lower connection portions are adapted to be deformed withinelastically deformable ranges so that, when the vertically middleportions of the front and rear rigid wall portions are pressed to bedisplaced toward each other to positions spaced a distance which is onehalf an original distance between the middle portions, the upper andlower edges of the rigid wall portions are displaced to follow thedisplacement of the middle portions of the front and rear rigid wallportions. Further, the left and right connection wall portions and theupper and lower connection portions may be adapted to be deformed withinthe elastically deformable ranges even if the front and rear rigid wallportions are squeezed to abut against each other.

The inventive delaminatable laminated bottle may further comprise amouth plug provided in the mouth portion thereof. The mouth plug has anoutlet passage through which fluid contained in the inner layer bag isdischarged to the outside. The mouth plug may include a dispense valveprovided in the outlet passage for opening and closing the outletpassage. The dispense valve may include a valve flange and a valve head,which are preferably connected to each other via a valve sleeve having aflexible structure. The valve flange seals an inner periphery of theoutlet passage. The valve head is connected to an inner periphery of thevalve flange directly or indirectly via the valve sleeve or the like,and has an orifice which is opened to permit the fluid to flow when apredetermined dispense pressure is applied to the inside of the bag andis closed to prevent the flow of the fluid when the predetermineddispense pressure is removed. Further, the mouth plug may have a supportportion which supports the valve head in abutment with the valve head toprevent the orifice of the valve head from being opened when a negativepressure occurs inside the bag. The inside pressure of the bottle shouldbe increased to not lower than the predetermined dispense pressure toopen the dispense valve. Since the bottle having the aforesaidconstruction can be squeezed to be significantly elastically deformed bypressing the entire body of the bottle, it is possible to apply thedispense pressure to the bottle without breakage.

In the inventive delaminatable laminated bottle, a check valve is absentin the introduction hole. Further, the peripheral wall of the body ofthe outer layer bottle may have a recess indented inward of the bottleor a protuberance projecting outward of the bottle, and the introductionhole may be provided in the recess or the protuberance. The recess orthe protuberance is dimensioned so as to be covered with a finger padand, for example, has a round shape having a diameter of about 5 mm.Thus, a portion of the bottle body to be pressed by the finger isclearly defined, so that even a blind person or a handicapped person caneasily use the bottle. Further, the recess or the protuberance can beaccurately positioned and shaped by the blow-molding mold. Where theintroduction hole is formed in the preform before the blow molding, theposition and configuration of the introduction hole of the bottle areliable to be varied after the blow molding. With the provision of theintroduction hole in the recess or the protuberance, however, thepositional and configurational variations are less conspicuous, therebyimproving the appearance of the product.

According to the present invention, a production method for adelaminatable laminated bottle which includes an outer layer and aninner layer provided on an inner surface of the outer layer anddelaminatable from the outer layer, the outer layer having anintroduction hole for introducing air into a space between the outerlayer and the inner layer comprises the steps of: injection-molding anouter layer preform; injection-molding an inner layer preform inside theouter layer preform; blow-molding the delaminatable laminated bottlefrom a laminate parison including the outer layer preform and the innerlayer preform; and performing a defective checking operation.

In the outer layer preform injection molding step, the introduction holemay be formed in the outer layer preform, and a test hole may be formedin a mouth portion of the outer layer preform. In the inner layerpreform injection molding step, the inner layer preform may beinjection-molded with pins being inserted in the introduction hole andthe test hole from an outer periphery of the outer layer preform andwith distal ends of the pins being flush with an inner surface of theouter layer preform. In the blow molding step, the parison may beblow-molded with the introduction hole being positioned in apredetermined circumferential position with respect to a blow-moldingmold. In the defective checking step, air communication between the testhole and the introduction hole of the delaminatable laminated bottleproduced by the blow molding is checked for detecting defectiveness ofthe introduction hole. Thus, even if a portion of the parison (e.g., abody of the parison) formed with the introduction hole is drawn in theblow molding step, it is possible to check if the introduction hole isclosed by the drawing.

In the inventive production method, the air communication check isperformed by introducing air from the test hole.

The introduction hole of the outer layer preform has a diameter which isnot greater than twice, more preferably not greater than 1.5 times athickness of a portion of the inner layer preform adjacent to theintroduction hole. This prevents the introduction hole from being buriedin the inner layer by a blow pressure in the blow molding.

Further, the outer layer may comprise an outer layer bottle having asqueeze-deformable bottomed tubular body, a shoulder portion and a mouthportion connected to an upper edge of the body via the shoulder portion,and the inner layer may comprise an inner layer bag provided on an innersurface of the outer layer bottle and delaminatable from the outer layerbottle. The introduction hole may be provided in a peripheral wall ofthe body of the outer layer bottle. The blow-molding mold has a shapeimparting surface which includes a shape imparting surface portion forforming a recess or a protuberance in a predetermined portion of theperipheral wall of the outer layer bottle including the introductionhole. With this arrangement, the recess or the protuberance is formed ina portion of the bottle body to be pressed by a finger for clearlymarking the press portion, so that even a blind person or a handicappedperson can easily use the bottle. With the provision of the introductionhole in the recess or the protuberance, positional and configurationalvariations of the introduction hole are less conspicuous, therebyimproving the appearance of the product.

In the inventive production method, it is possible to employ a methodand an apparatus for forming a hole only in an outer layer which aredisclosed in JP-2001-105477-A.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of an eyedropper including adelaminatable laminated bottle according to one embodiment of thepresent invention;

FIG. 2 is a vertical sectional view illustrating how to use theeyedropper;

FIGS. 3( a) and 3(b) are a plan view and a front view, respectively,illustrating the overall delaminatable laminated bottle of theeyedropper;

FIG. 4 is a side view of the delaminatable laminated bottle;

FIG. 5 is a sectional view taken along a line A-A in FIG. 4;

FIG. 6 is a sectional view taken along a line B-B in FIG. 3 [FIG. 3(b)];

FIG. 7 is a vertical sectional view of a mold for illustrating an outerlayer preform injection molding step of a delaminatable laminated bottleproduction method according to another embodiment of the presentinvention;

FIG. 8 is a vertical sectional view of a mold for illustrating an innerlayer preform injection molding step of the production method;

FIGS. 9( a) and 9(b) illustrate a laminate parison as an intermediateproduct obtained by the production method, particularly, FIG. 9( a) is asectional view of a axially middle portion of the parison (taken along aline D-D in FIG. 9(b)), and FIG. 9( b) is a vertical sectional view ofthe parison taken along a line C-C;

FIG. 10 is a schematic vertical sectional view illustrating ablow-molding mold employed in a blow molding step of the productionmethod as corresponding to the sectional view taken along the line C-Cin FIG. 9; and

FIG. 11 is a schematic diagram illustrating a defective product checkingstep of the production method.

BEST MODE FOR CARRYING OUT THE INVENTION

FIGS. 1 and 2 illustrate an eyedropper 10 as a dispenser including adelaminatable laminated bottle according to one embodiment of thepresent invention. The eyedropper 10 includes a delaminatable laminatedbottle 11 of a double layer structure blow-molded from a bottomedtubular laminate parison, a mouth plug 12 attached to a mouth portion 11a of the bottle 11, and a protection cap 13. When a user removes the cap13 and holds the laminated bottle 11 upside down to press and squeeze abody 11 b of the laminated bottle 11, an eye lotion (fluid) in thebottle 11 flows through an outlet passage in the mouth plug 12 therebyto be dropped from a distal nozzle portion 15. Although the bottle 11 isillustrated on an enlarged scale in the figures, the bottle 11 actuallyhas a total height of about 56 mm, and the body 11 b has a lateral widthof about 25 mm and an anteroposterior thickness of about 17.5 mm. Thebottle 11 has a volume of about 10.4 ml.

The laminated bottle 11 has a laminate structure which includes an outerlayer bottle 1 (squeeze bottle) defined as an outer layer and an innerlayer bag 16 (fluid containing bag) defined as an inner layer. The outerlayer bottle 1 and the inner layer bag 16 each have a cylindrical mouthportion and a body having a flat cross section immediately after theblow molding. The outer layer bottle 1 is composed of a synthetic resinsuch as PET or EVOH, and the inner layer bag 16 is composed of asynthetic resin (e.g., a polyolefin such as polyethylene) which iseasily delaminatable from the outer layer bottle 1. The mouth portion ofthe bag 16 defines an opening for discharging liquid.

As also shown in FIGS. 3 to 6, the outer layer bottle 1 is such that acylindrical mouth portion 4 is connected to an upper end of anelastically squeeze-deformable bottomed tubular body 2 via a shoulderportion 3 having a diameter gradually decreasing toward its upper end.As shown in FIG. 6, the body 2 has a flat oval peripheral wall whichincludes front and rear rigid wall portions 5 spaced a predetermineddistance in opposed relation, left and right flexible connection wallportions 6 respectively connecting left and right edges of the frontrigid wall portion to left and right edges of the rear rigid wallportion, and has an anteroposterior thickness which is smaller than alateral width thereof. The rigid wall portions 5 (front and rear wallportions) each have a vertically elongated rectangular shape as viewedfrom the front side, and are generally planar in cross section andvertical section. The cross section and the vertical section are notnecessarily required to be completely planar, but may be slightlycurved. The flexible connection wall portions 6 (left and right wallportions) each have an arcuate shape with an anteroposteriorly middleportion thereof projecting laterally outward, and each have a curvatureradius which is smaller than the length of the minor axis of the body 2.Upper edges of the rigid wall portions 5 are each connected to theshoulder portion 3 via a flexible upper connection portion 7, and loweredges of the rigid wall portions 5 are each connected to a bottomportion 2 a of the body 2 via a flexible lower connection portion 8.Thus, the peripheries of the rigid wall portions 5 are each surroundedonly by the flexible portions 6, 7, 8. Further, the front and rear rigidwall portions 5 are integrally connected to the bottom portion 2 a andthe shoulder portion 3 only by the flexible portions 6, 7, 8.

The flexible upper connection portion 7 and the flexible lowerconnection portion 8 are located anteroposteriorly outward of the rigidwall portions 5. Therefore, when the bottle 1 is blow-molded from theplastic parison, portions of the parison corresponding to the connectionportions 7, 8 are stretched at a higher stretch ratio, so that theconnection portions 7, 8 are formed as having a relatively smallthickness. As a result, the connection portions 7, 8 each haveflexibility sufficient for easy deformation. On the other hand, therigid wall portions 5 each have a greater thickness and, hence, aredifficult to deform with high rigidity. The average thickness of theconnection portions 7, 8 are preferably smaller than one half theaverage thickness of the rigid wall portions 5.

The lateral width of the body 2 of the squeeze bottle 1 is greater than1.5 times the anteroposterior thickness of the body 2 (i.e., a distancebetween outer surfaces of the front and rear rigid wall portions 5). Inthe blow molding, portions of the parison corresponding to the left andright connection wall portions 6 are stretched at a higher stretchratio, so that the average thickness of the left and right flexibleconnection wall portions 6 is smaller than the average thickness of therigid wall portions 5. In the blow molding, portions of the parisoncorresponding to the rigid wall portions 5 may have a greater thicknessthan the portions of the parison corresponding to the flexibleconnection wall portions.

When vertically middle portions of the front and rear rigid wallportions 5 of the outer layer bottle 1 having the aforesaid constructionare pressed by two fingers to be displaced toward each other topositions spaced a distance which is one half the original distancebetween the middle portions, the left and right connection portions 6and the upper and lower connection portions 7, 8 are deformable withinan elastically deformable range so that the upper and lower edges of therigid wall portions 5 follow the displacement of the middle portions.

In this embodiment, an introduction hole 17 for introducing outside airinto a space between the bottle body 2 and a body 16 b of the bag 16 isprovided in a center portion of the front rigid wall portion 5 (frontwall portion) of the outer layer bottle 1. The introduction hole 17extends through the outer layer bottle 1 from the inner surface to theouter surface of the outer layer bottle, but the inner layer bag 16 hasno introduction hole. Further, a round recess 18 having a greaterdiameter than the introduction hole 17 is provided in the center portionof the rigid wall portion 5. The recess 18 is indented inward of thebottle, and the diameter thereof is about 5 mm. The introduction hole 17is provided in the recess 18. The introduction hole 17 can be closed byclosing the recess 18 by a finger. The introduction hole 17 has no checkvalve and, hence, is always open. The introduction hole 17 has anopening area of about 1 mm² to about 2 mm².

Test holes 19 are provided in a vertically middle portion of the mouthportion 4 of the outer layer bottle 1 as communicating with theintroduction hole 17 via the space between the outer layer bottle 1 andthe inner layer bag 16. In this embodiment, two test holes 19 areprovided at diametrically opposite positions. The test holes 19 alsoextend through the outer layer bottle 1 from the inner surface to theouter surface of the outer layer bottle, but the inner layer bag 16 hasno test hole. The test holes 19 are closed from the inside by a mouthportion 16 a of the inner layer bag 16, so that air between the outerlayer 1 and the inner layer 16 is prevented from flowing out of the testholes 19 during use of the eyedropper 10. In order to assuredly closethe test holes by the inner layer bag 16, the mouth portion 16 a of theinner layer bag 16 is pressed against the test holes by an inside plug21 to be described layer in this embodiment. Thus, the test holes 19 areclosed by the inner layer bag 16 and the inside plug 21.

The body 16 b of the inner layer bag 16 is of a film shape, and iseasily deformable to be shrunk as the volume of the contents is reduced.On the other hand, the mouth portion 16 a of the inner layer bag 16 hasa greater thickness than the body 16 b, and can recover its originalcylindrical shape. The center of a bottom portion of the bag 16 is fixedto the center of the bottom portion of the outer layer bottle 1, so thatthe bottom portion of the bag 16 is prevented from being lifted.

The mouth plug 12 mainly includes an inside plug 21 fitted in the bottlemouth portion 4 and a nozzle cap 22 axially connected to the inside plug21 and fitted around the bottle mouth portion 4.

The inside plug 21 is such that a first cylindrical portion 21 a withits proximal end abutting against a distal end surface of the bottlemouth portion 4 and a second cylindrical portion 21 b disposed in thefirst cylindrical portion 21 a are integrally connected to each othervia a flange 21 c projecting radially outward from a distal edge of thesecond cylindrical portion 21 b. A proximal end portion of the secondcylindrical portion 21 b extends much further than the proximal end ofthe first cylindrical portion 21 a toward the proximal end of the insideplug (downward in FIG. 1), so that the second cylindrical portion 21 bis fitted in the bottle mouth portion 4 in a gas-tight and liquid-tightmanner. Particularly in this embodiment, the second cylindrical portion21 b extends further downward of the test holes 19 which are gas-tightlyclosed from the inside by the second cylindrical portion 21 b.

A horizontal planar support wall portion 21 d is provided in an axiallymiddle portion of the second cylindrical portion 21 b. The support wallportion 21 d has four through-holes 23 (outlet passage) provided in aperipheral portion thereof around the center thereof as extendingaxially therethrough. A recess in which a connector sleeve 24 a and avalve head 24 b of a dispense valve 24 to be described later are fittedis provided above the support wall portion 21 d.

The nozzle cap 22 is a generally cylindrical member, which includes atop plate provided with the nozzle portion 15 at its axially distal end.The first cylindrical portion 21 a of the inside plug 21 is fitted inthe nozzle cap 22. The nozzle cap 22 has a smaller diameter cylindricalportion provided in a distal outer peripheral portion thereof with astep. The protective cap 13 is threadingly fitted around the smallerdiameter cylindrical portion.

A thin plate filter 25 is provided in a center portion of a lowersurface of the top plate of the nozzle cap 22. Examples of the filter 25include a membrane filter, a sintered filter, a hydrophilic porousplanar film and a hydrophobic porous planar film, which are capable ofpreventing passage of pathogenic bacteria from a downstream side to anupstream side of the outlet passage (from the outside to the inside ofthe bottle). The filter 25 is disposed downstream of the dispense valve24. In the illustrated example, the filter is disposed adjacent thenozzle portion 15, and held above the inside plug 21 by a holder 26fitted in the nozzle cap 22. The holder 26 has a through-hole 26 athrough which the content liquid flows into the filter 25. Therefore,the outlet passage of the mouth plug 12 communicating between the insideof the bag 16 and the outside of the bottle is constituted by thethrough-holes 23, a cavity, the through-hole 26 a and an inside passageof the nozzle portion 15.

The dispense valve 24 is constituted by a valve flange 24 c, the valvehead 24 b and the connector sleeve 24 a which are integrally formed ofan elastic material such as a silicone rubber.

The valve flange 24 c is a generally ring member, which has a triangularcross section having a thickness gradually increasing toward its outerperiphery. The valve flange 24 c is held vertically between the insideplug 21 and the nozzle cap 22 in a gas-tight and liquid-tight manner toair-tightly and liquid-tightly seal the inner periphery of the outletpassage.

The valve head 24 b has a semispherical shape which is round as seen inplan and concavely curved inwardly of the bottle, and has an orifice ofa cross shape incised in a center portion thereof. The orifice is openedto permit the fluid (content liquid) to flow from the inside of theinner layer bag 16 when a predetermined dispense pressure is applied toan inner surface of the head 24 b, and closed to block the flow of thefluid when the predetermined dispense pressure is removed. A lowersurface of the valve head 24 b has a generally flat center portion, andthe orifice 24 d is provided in the flat surface portion. The flatsurface portion of the valve head 24 b usually abuts against an uppersurface of the support wall portion 21 d.

The connector sleeve 24 a has a generally cylindrical shape with its oneaxial end integrally connected to an inner peripheral edge of the valveflange 24 c and with its other axial end integrally connected to anouter peripheral edge of the valve head 24 b. The connector sleeve 24 ahas a relatively thin flexible structure so as to be easily deformable.Thus, when a predetermined pressure smaller than the aforesaidpredetermined dispense pressure is applied to the inner surface of thevalve head 24 b, the valve head 24 b is displaced downstream (toward thedistal end) with the orifice 24 d kept closed. As a result, theconnector sleeve 24 a is elastically deformed to be lifted. When thepredetermined smaller pressure is removed, the connector sleeve 24 arecovers its original shape, whereby the valve head 24 b is displacedupstream (toward the proximal end) with the orifice 24 d kept closed. Asa result, the fluid remaining in the nozzle inside passage is suckedback to the upstream side of the filter. A fluid suction force may beprovided by the recovery force of the connector sleeve 24 a or by anegative pressure applied to the inner surface of the head 24 b.

The structure of the connector sleeve 24 a is not limited to that shownin the figure, but may have an elastically deformable bellow structurewhich is axially shrinkable.

In the eyedropper 10, the valve head 24 b is deformed toward the distalend with the orifice 24 d of the dispense valve 24 kept closed when theinside pressure is increased within a range smaller than thepredetermined dispense pressure due to a temperature change or duringcarrying of the eyedropper. The inside pressure is reduced according tothe amount of the displacement of the valve head 24 b, so that thepressure increase is alleviated. For dispensing the content liquid fromthe nozzle portion 15, the user holds the bottle 11 upside down andpresses the body 2 of the outer layer bottle 1 radially inward fromopposite sides of the minor axis of the bottle with the introductionhole 17 closed by the finger as shown in FIG. 2. Thus, the outer layerbottle 1 is squeezed to be deformed to pressurize the air in the spacebetween the outer layer 1 and the inner layer 16, whereby the innerlayer bag 16 is compressed. When an inside pressure not smaller than thepredetermined dispense pressure is thus applied to the inner surface ofthe head 24 b, the orifice 24 d of the dispense valve 24 is opened todrop the content liquid from the inner layer bag 16 through the nozzleportion 15. When the user stops pressing the bottle 11 and releases thefinger from the introduction hole 17, outside air is introduced into thespace between the outer layer 1 and the inner layer 16 from theintroduction hole 17. At this time, the valve head 24 b first recoversits original shape to close the orifice 24 d, and then the connectorsleeve 24 a recovers its original shape. When the sleeve 24 a recoversits original shape, the content liquid remaining in the nozzle insidepassage (i.e., a distal opening of the outlet passage) is sucked backinto the cavity upstream of the filter 25. Then, the content liquid isretained in the cavity which is isolated from the outside air.

When the pressing of the delaminatable bottle 11 is stopped, the outerlayer bottle 1 recovers its original shape, but the inner layer bag 16does not recover its original shape without the back-flow of the contentliquid into the inner layer bag 16 and without the introduction of theoutside air because the orifice 24 d is closed. Therefore, the innerlayer bag is shrunk as the volume of the content liquid is reduced. Onthe other hand, when the outer layer bottle 1 recovers its originalshape, air is introduced into the space between the inner layer bag 16and the outer layer bottle 1 through the introduction hole 17. Even if anegative pressure occurs inside the inner layer 16 at this time to applya force to the valve head 24 b of the dispense valve 24 to deform thevalve head inward of the bottle, the orifice is opened by the inwarddeformation of the head 24 b and, therefore, the outside air isprevented from flowing into the inner layer bag 16. This is because thehead 24 b is supported in abutment against the support wall portion 21 dand, hence, has a flexible structure as described above.

Next, a production method and a production apparatus for theaforementioned delaminatable laminated bottle will be explained by wayof embodiments thereof with reference to FIGS. 7 to 11.

The production method according to this embodiment includes the steps ofinjection-molding an outer layer preform 1P (see FIG. 7),injection-molding an inner layer preform 16P on the entire inner surfaceof the outer layer preform 1P (see FIG. 8), blow-molding thedelaminatable laminated bottle 11 in a biaxially stretchable manner froma laminate parison P (see FIG. 9) including the outer layer preform 1Pand the inner layer preform 16P (see FIG. 10), and performing adefective checking operation (see FIG. 11).

The outer layer preform 1P and the inner layer preform 16P are molded bymeans of an injection station shown in FIGS. 7 and 8. In thisembodiment, the outer layer preform and then the inner layer preform aremolded in the same position in the same station by changing an injectioncore. However, a mold for the injection molding of the outer layerpreform and a mold for the injection molding of the inner layer preformmay be separately provided.

FIG. 7 illustrates the step of molding the outer layer preform 1P. Inthis figure, the injection-molding mold includes injection cores 50A,50B and a cavity mold 51. After the injection core and the cavity moldare vertically combined with each other and clamped, a melted resin isinjected into the cavity through a hot runner and a hot runner nozzle tomold the outer layer preform 1P.

Pins 52, 53 for forming the introduction hole 17 and the test holes 19are provided in positions in the cavity mold 51. These pins 52, 53project radially inward from the cavity mold 51. Distal ends of the pinsabut against a side surface of the injection core 50A during theinjection of the melted resin (before the start of the injection orafter the injection before the resin is cured). When the outer layerpreform 1P is molded, the introduction hole 17 and the test holes 19 areformed as extending through the outer layer preform by these pins 52,53. The pins 52, 53 are adapted to be withdrawn radially outward fromthe introduction hole 17 and the test holes 19 by opening the cavitymold.

FIG. 8 illustrates the step of molding the inner layer preform 16P. Astate illustrated in FIG. 8 is such that another injection core 50B forthe inner layer is inserted after the outer layer preform 1P is moldedand the injection core 50A for the outer layer is withdrawn. The pins52, 53 are kept in the state shown in FIG. 7. That is, the pins 52, 53are inserted from the outer periphery with the distal ends thereof beingflush with the inner surface of the outer layer preform 1P. The innerlayer injection core 50B has a diameter which is smaller than the outerlayer injection core 50A by the thickness of the inner layer preform16P. The injection core 50B may have a resin flow path and a gate forinjecting a melted resin for the inner layer preform 16P into a cavity.

After the inner layer preform 16P is molded, the injection-molding moldis opened to take out the laminate parison P, which is in turntransported to a blow station. As shown in FIG. 9, portions of a body ofthe laminate parison P corresponding to the rigid wall portions 5 of thebottle 1 have a greater thickness than portions of the laminate parisonP corresponding to the connection wall portions 6, 7. The laminateparison P has a positioning reference portion Ps (see FIGS. 4 and 5)provided in a predetermined circumferential position on an outerperiphery of a mouth portion of the laminate parison P for positioningthe laminate parison P circumferentially with respect to a mold for theblow molding. The introduction hole 17 of the outer layer preform 1P hasa diameter of about 0.7 mm, and a portion of the inner layer preform 16Padjacent to the introduction hole has a thickness of about 0.8 mm.

In the blow station shown in FIG. 10, the delaminatable laminated bottle11 is blow-molded from the parison P with the use of the blow-moldingmold which includes a blow core 61 fitted with a draw rod 60, a lip mold62 for holding the parison P, a blow cavity mold 63 and a bottom mold64. A shape imparting surface of the blow cavity mold 63 includes ashape imparting surface portion 63 a for forming the recess 18 in thecenter portion of the rigid wall portion 5 of the outer layer bottle 1around the introduction hole 17.

When the parison P is inserted in the blow-molding mold, the parison Pis first rotated so that the reference portion Ps of the parison P islocated in a predetermined angular position with respect to theblow-molding mold. The positional adjustment may be performed bypressing the reference portion Ps by mechanical contact or by rotatingthe parison P while checking the position of the reference portion Ps byan optical sensor, a CCD camera or the like. When the blow-molding moldis clamped, the parison P is fixed in an accurate position with thereference portion Ps being held by the mold. The temperature of theparison P is preliminarily adjusted before the parison P is insertedinto the blow-molding mold.

After the clamping of the blow-molding mold, the parison P is firstvertically drawn by moving down the draw rod 60 to press the bottom ofthe bottomed cylindrical parison P downward. Then, pressurized air isintroduced into the parison P from the blow core 61 to laterally drawthe parison P, whereby the body of the parison P is pressed against theshape imparting surface of the cavity mold 63. Thus, the bottle body isshaped. At this time, the portion (bottle mouth portion) of the parisonformed with the test holes 19 is held by the lip mold 62 and, therefore,is not drawn. However, a portion of the parison downward of the testholes 19 is drawn. The portion of the parison formed with theintroduction hole 17 is vertically and laterally drawn. However, thepositional and configurational variations of the introduction hole 17formed in the bottle after the blow molding are less conspicuous,because the blow molding is performed with the introduction hole 17being located in the shape imparting surface portion 63 a. When theparison is laterally drawn, the introduction hole 17 is prevented frombeing buried in the inner layer preform 16P because the thickness of theportion of the inner layer preform 16P around the introduction hole 17is greater than the diameter of the introduction hole 17. The thicknessis not greater than about twice the diameter of the introduction hole17.

After the blow molding, the delaminatable laminated bottle 11 thusmolded is taken out. The inner layer bag 16 is preferably oncedelaminated from the outer layer bottle 1 by sucking air out of theinner layer bag 16 by vacuum.

In the defective checking step shown in FIG. 11, an injection nozzle 70connected to a pump is inserted in the test hole 19, and air is injectedinto the space between the outer layer bottle 1 and the inner layer bag16 from the test hole 19 through the injection nozzle 70. An aircommunication detection sensor 71 such as a pressure sensor is providedin the vicinity of the introduction hole 17. Whether or not the airflows out of the introduction hole 17 is checked during the injection ofthe air from the test hole 19. By inputting a detection signal from thesensor to a control device 72 such as a computer, an air communicationtest is performed for checking the air communication between the testhole 19 and the introduction hole 17, whereby defectiveness of theintroduction hole 17 is checked. A production line is designed so thatdefective bottles are automatically screened out based on the result ofthe check.

The present invention is not limited to the arrangements described inthe embodiments, but may be arbitrarily modified within a technicalscope defined by the appended claims.

According to the present invention, check means for checkingdefectiveness of the outside air introduction hole is provided for thesmall delaminatable laminated bottle, particularly for an eyedropperhaving a volume of about 10 ml. Even without the provision of a checkvalve in the introduction hole, the introduction hole can be easilyclosed when the bottle body is squeezed. The air in the space betweenthe inner layer and the outer layer is assuredly compressed to dispensea relatively great amount of content liquid at a time by squeezing thebottle body.

1. A delaminatable laminated bottle comprising: an outer layer bottlehaving a squeeze-deformable bottomed tubular body, a shoulder portionand a mouth portion connected to an upper edge of the body via theshoulder portion; an inner layer bag provided on an inner surface of theouter layer bottle and delaminatable from the outer layer bottle; theouter layer bottle having an introduction hole for introducing outsideair into a space between the outer layer bottle and the inner layer bag;the mouth portion having a test hole communicating with the introductionhole via the space between the outer layer bottle and the inner layerbag; and a member fitted in the mouth portion and having an outletpassage for dispensing contents of the inner layer bag, the memberpressing the inner layer bag against the test hole so that the test holeis closed by the inner layer bag and the member.
 2. A delaminatablelaminated bottle as set forth in claim 1, wherein the body of the outerlayer bottle has a flat tubular peripheral wall which includes a pair offront and rear wall portions spaced a predetermined distance in opposedrelation and left and right wall portions respectively connecting leftand right edges of the front wall portion to left and right edges of therear wall portion, and has an anteroposterior thickness which is smallerthan a lateral width thereof, wherein the left and right wall portionseach have an arcuate shape with an anteroposteriorly middle portionthereof bulged laterally outward, wherein the body further has an upperconnection portion which connects upper edges of the front and rear wallportions to the shoulder portion, and a lower connection portion whichconnects lower edges of the front and rear wall portions to a bottomportion thereof, wherein the introduction hole is provided in a centerportion of at least one of the front wall portion and the rear wallportion, and wherein the introduction hole is adapted to be closed by afinger when the body is squeezed to be deformed by pressing the frontand rear wall portions by the finger.
 3. A delaminatable laminatedbottle as set forth in claim 2, wherein a check valve is absent in theintroduction hole.
 4. A delaminatable laminated bottle as set forth inclaim 1, wherein the peripheral wall of the body of the outer layerbottle has a recess indented inward of the outer layer bottle or aprotuberance projecting outward of the outer layer bottle, and theintroduction hole is provided in the recess or the protuberance.
 5. Adelaminatable laminated bottle comprising: an outer layer bottle havinga squeeze-deformable bottomed tubular body, a shoulder portion and amouth portion connected to an upper edge of the body via the shoulderportion; and an inner layer bag provided on an inner surface of theouter layer bottle and delaminatable from the outer layer bottle;wherein the outer layer bottle has an introduction hole for introducingoutside air into a space between the outer layer bottle and the innerlayer bag; wherein the body of the outer layer bottle has a flat tubularperipheral wall which includes a pair of generally flat front and rearwall portions spaced a predetermined distance in opposed relation andleft and right wall portions respectively connecting left and rightedges of the front wall portion to left and right edges of the rear wallportion, and has an anteroposterior thickness which is smaller than alateral width thereof, wherein the left and right wall portions eachhave an arcuate shape with an anteroposteriorly middle portion thereofbulged laterally outward, wherein the body further has an upperconnection portion which connects upper edges of the front and rear wallportions to the shoulder portion, and a lower connection portion whichconnects lower edges of the front and rear wall portions to a bottomportion thereof, wherein the introduction hole is provided in a centerportion of at least one of the front wall portion and the rear wallportion, wherein the introduction hole is adapted to be closed by afinger when the body is squeezed to be deformed by pressing the frontand rear wall portions by the finger.
 6. A delaminatable laminatedbottle as set forth in claim 5, wherein a check valve is absent in theintroduction hole.
 7. A delaminatable laminated bottle as set forth inclaim 5, wherein the peripheral wall of the body of the outer layerbottle has a recess indented inward of the outer layer bottle or aprotuberance projecting outward of the outer layer bottle, and theintroduction hole is provided in the recess or the protuberance.
 8. Aproduction method for a delaminatable laminated bottle which includes anouter layer and an inner layer provided on an inner surface of the outerlayer and delaminatable from the outer layer, the outer layer having anintroduction hole for introducing air into a space between the outerlayer and the inner layer, the method comprising the steps of:injection-molding an outer layer preform; injection-molding an innerlayer preform inside the outer layer preform; blow-molding thedelaminatable laminated bottle from a laminate parison including theouter layer preform and the inner layer preform; and performing adefective checking operation, wherein the introduction hole is formed inthe outer layer preform, and a test hole is formed in a mouth portion ofthe outer layer preform in the outer layer preform injection moldingstep, wherein the inner layer preform is injection-molded with pinsbeing inserted in the introduction hole and the test hole from an outerperiphery of the outer layer preform and with distal ends of the pinsbeing flush with an inner surface of the outer layer preform in theinner layer preform injection molding step, wherein the parison isblow-molded with the introduction hole being located in a predeterminedcircumferential position with respect to a blow-molding mold in the blowmolding step, wherein air communication between the test hole and theintroduction hole of the delaminatable laminated bottle produced by theblow molding is checked for detecting defectiveness of the introductionhole in the defective checking step.
 9. A delaminatable laminated bottleproduction method as set forth in claim 8, wherein the air communicationcheck is performed by introducing air from the test hole.
 10. Adelaminatable laminated bottle production method as set forth in claim8, wherein the introduction hole of the outer layer preform has adiameter which is not greater than twice a thickness of a portion of theinner layer preform adjacent to the introduction hole.
 11. Adelaminatable laminated bottle production method as set forth in claim8, wherein the outer layer comprises an outer layer bottle having asqueeze-deformable bottomed tubular body, a shoulder portion and a mouthportion connected to an upper edge of the body via the shoulder portion,wherein the inner layer comprises an inner layer bag provided on aninner surface of the outer layer bottle and delaminatable from the outerlayer bottle, wherein the introduction hole is provided in a peripheralwall of the body of the outer layer bottle, wherein the blow-moldingmold has a shape imparting surface which includes a shape impartingsurface portion for forming a recess or a protuberance in apredetermined portion of the peripheral wall of the outer layer bottleincluding the introduction hole.